Linear motor systems are well known to the art and typically comprise linear motors, such as, for example, two-dimensional or X-Y linear motors of the type described, for example, in U. S. Pat. No. 4,823,062 issued Apr. 14, 1989. The linear motors typically move along a ferromagnetic stator or platen having a regular grid work of square-shaped teeth arranged in an orthogonal pattern of spaced parallel rows and spaced parallel columns. The linear motor which may, for example, be of the type manufactured by Xynetics Corporation, generates moving electromagnetic fields in mutually perpendicular (X and Y directions) which cooperate with the ferromagnetic working surface of the platen comprised of the aforementioned grid work of teeth to move the linear motor to any desired position along the platen working surface typically to an accuracy which is at least as small as 0.001 inches. The electromagnetic fields passing through the platen generate considerable eddy current heating. In addition, the heating is quite localized causing the development of hot spots. Such uneven heating leads to dimensional degradation of the platen.
It is thus important to provide a platen capable of use with linear motors which may operate continuously for long periods of time while at the same time preventing or substantially eliminating dimensional degradation of the highly accurately machined tooth pattern formed upon the working surface of the platen.